Meltblown nonwoven fibrous webs are used for a variety of purposes including filtration (e.g., flat web and pleated filters), insulation, padding and textile substitutes. Patents or applications relating to nonwoven webs or their manufacture include U.S. Pat. Nos. 3,981,650 (Page), 4,100,324 (Anderson), 4,118,531 (Hauser), 4,818,464 (Lau), 4,931,355 (Radwanski et al.), 4,988,560 (Meyer et al.), 5,227,107 (Dickenson et al.), 5,273,565 (Milligan et al.), 5,382,400 (Pike et al. '400), 5,679,042 (Varona), 5,679,379 (Fabbricante et al.), 5,695,376 (Datta et al.), 5,707,468 (Arnold et al.), 5,721,180 (Pike et al. '180), 5,877,098 (Tanaka et al.), 5,902,540 (Kwok), 5,904,298 (Kwok et al.), 5,993,543 (Bodaghi et al.), 6,176,955 B1 (Haynes et al.), 6,183,670 B1 (Torobin et al.), 6,230,901 B1 (Ogata et al.), 6,319,865 B1 (Mikami), 6,607,624 B2 (Berrigan et al. '624), 6,667,254 B1 (Thompson et al.), 6,858,297 B1 (Shah et al.) and 6,916,752 B2 (Berrigan et al. '752); European Patent No. EP 0 322 136 B1 (Minnesota Mining and Manufacturing Co.); Japanese published application Nos. JP 2001-049560 (Nissan Motor Co. Ltd.), JP 2002-180331 (Chisso Corp. '331) and JP 2002-348737 (Chisso Corp. '737); and U.S. Patent Application Publication No. US2004/0097155 A1 (Olson et al.). Patents or applications relating to pleated filters include U.S. Pat. Nos. 4,547,950 (Thompson), 5,240,479 (Bachinski), 5,709,735 (Midkiff et al.), 5,820,645 (Murphy, Jr.), 6,165,244 (Choi), 6,521,011 B1 (Sundet et al. '011), 6,740,137 B2 (Kubokawa et al.) and D449,100 S (Sundet et al. '100), and U.S. Patent Application Publication Nos. US 2003/0089090 A1 (Sundet et al. '090), US 2003/0089091 A1 (Sundet et al. '091) and US2005/0217226 A1 (Sundet et al. '226).